Pipe wrench having a pivoted yoke carrying an adjustable jaw



Sept. 7, 1948. c, MEAD 2,448,999

PIPE WRENCH HAVING A PIVOTED YOKE CARRYING AN ADJUSTABLE J'AW Filed June 12, 1944 INVENTOR 'Iawren ce CIMead I ATTORNEYS Patented Sept. 7, 1943 UNITED STATES, PATENT OFFICE PIPE WRENCH HAVING A PIVOTED YOKE CARRYING AN ADJUSTABLE JAW Lawrence C. Mead, Turlock, Calif.

Application June 12, 1944, Serial No. 539,804

a 3 Claims. (01. s1 -10s) the wrench shown in my Patent No. 2,315,807,

dated April 6, 1943.

The principal objects of the present invention are to provide an improved mounting of the pawl-block which engages the teeth of the movable jaw so that said block has a larger bearing area in the yoke, while enabling the latter to be thinner than was previously the case; an improved spring arrangement to yieldably hold the block in its bearing so that the spring is not exposed; and an improved yieldable stop arrangement between the movable shank and yoke which prevents possible breakage of the spring if the eshank is pulled out suddenly against the stop.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a fragmentary sectional of a pipe wrench showing the improved features incorporated therein.

Figure 2 is a fragmentary side elevation of the wrench, the yoke being partly broken out to show the yieldable shop as engaged.

Figure 3 is an enlarged plan of the pawl block and cooperating spring detached.

Referring now more particularly to the characters of reference on the drawings, the wrench is of the same general form and includes the essential features of the previous wrenches. It comprises a handle I terminating in a relatively deep portion 2, at the outer end of which is a fixed jaw 3. Mounted in the portion 2 intermediate its ends is a cross pin 4 which forms the pivot mounting for a yoke 5 of U-shaped cross section. This yoke extends some distance beyond one edge 6 of the portion 2, said edge between the pivot and jaw being normally parallel to the back I of the yoke.

Slidable in the yoke in normal engagement with said edge 6 is a straight shank 8 having a jaw 9 at its outer end arranged to cooperate with the jaw 3. The working faces of the jaws are disposed at an obtuse angle to the edge 6 (and to the corresponding under edge of the shank 8) in such relation to the axis of the pin 4 that the latter may be relatively large and strong and 2 i hence have its axis some distance inwardly from the edge 6, while giving an advantageous leverage on the work at the point of contact of said jaw faces therewith.

Formed in the outer edge of the shank 8 is a row of ratchet teeth It] adapted to cooperate with the teeth of a holding pawl or block H of the same form as shown in said aforementioned copending'application. The block H is formed with a head 12 of not less than full semi-spherical form, which engages, for substantially its full depth, in a seat i3 pressed outwardly in the back I of the yoke 5. The inner end of the block is engaged by the free end of a spring I4 secured, as at IE, on the back of the yoke, and which may be a continuation of the spring l6 which extends from said point of securement in the opposite direction and engages the shank beyond the teeth It, as before.

The free end of the spring 14 is relativelynarrow and is bent down as at I! and transversely rounded, as shown in Fig. 3. Said end, as well as the adjacent end of the block II, is disposed on a slope at right angles to a line L drawn through the center of the head [2 from a point on the forward side of the seat l3 adjacent its rim, as shown in Fig. 1.

This arrangement insures a holding pressure against the block in a direction tending to maintain the head in firm engagement with its seat throughout the area thereof, while allowing said head to oscillate in any direction in the seat, as the relative movement between the loose fitting movable shank 8 and the yoke may necessitate. The spring l4 being located within the yoke is of course protected from all damage from exterior objects.

The shank engaging spring It is adapted to engage against an end stop lug I8 on the shank 8 when said shank is slid along to a point such that the endmost teeth iii engage the block therewith, so as to prevent undesired withdrawal of the shank from the yoke as in said Patent No. 2,315,807. In order toprevent an unduly abrupt contact of the spring with the stop, which might tend to snap the spring in the event of a sudden pulling pressure being imparted to the shank, the shank engaging end of the spring It is turned up or away from the shank at an acute angle therewith, as shown at I 9, while the adjacent or cooperating end of the stop lug is cut on a similar angle, as shown at 28. By reason of this arrangement, while the lug l8 cooperates with the spring It to eifectively stop further movement of the shank with ordinary pressures, it

3 enables the spring to yield and move up the lug if the pressure is excessive, and thus prevents possible fracture of the spring.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I.

claim as new and useful and desire to secure by Letters Patent is:

1. A Wren-ch comprising a handle,a fixed jaw on one end of the handle, a yoke pivoted on the handle adjacent the fixed jaw, a shank slidable in the yoke, a jaw depending from the outer end of the, shank and adapted to cooperate. with the fixed jaw, the back of the shank being spaced back of the shank and the back of the yoke and provided with a row of teeth for engagement with theteeth on the back of the shank, a semispherical head on the block seated in the cavity in the back of the yoke, and a. spring fixed on the inner surface of the back of the yoke and engaging the end of the block to hold the head in frictional engagement with the walls of said cavity.

2. A device as in claim 1, in which the end of the block engaged by the spring is sloped in a plane at substantially right angles to a line drawn through the axis of the head from a point at the side of the cavity opposite such block end.

3. A device as in claim 1 in which the spring is curved transversely at the point where it engages the block end.

LAWRENCE C. MEAD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number, 

